Why Correct Sizing Matters
One of the most common mistakes Zimbabwean solar buyers make is choosing a system that is too small. An undersized system means battery depletion, forced load-shedding, and reduced battery lifespan. An oversized system wastes capital. Getting sizing right starts with understanding your daily energy consumption.
Step 1: List All Your Appliances
Write down every electrical appliance you want your solar system to power. For each, note the power rating (Watts), quantity, and daily runtime (hours).
| Appliance | Typical Wattage | Daily Hours |
|---|---|---|
| LED Bulb (9W) | 9 W | 5–8 h |
| TV (42" LED) | 80–120 W | 4–6 h |
| Refrigerator (200L) | 100–180 W | 8–12 h (cycles) |
| Laptop | 45–90 W | 4–8 h |
| Router / Modem | 10–20 W | 24 h |
| Electric Kettle | 1,500–2,200 W | 0.25–0.5 h |
| Iron | 1,000–2,200 W | 0.5–1 h |
Step 2: Calculate Your Daily Load
For each appliance: Qty × Watts × Hours/Day = Wh/day. Sum all appliances.
Use our Solar System Sizing Calculator — enter your appliances and instantly get panel, battery, and inverter recommendations.
Step 3: Size Your Solar Panels
Zimbabwe receives 5.5–6 peak sun hours per day. Account for 20% system inefficiency:
Step 4: Size Your Battery Bank
Batteries must store enough for 2 days autonomy at maximum 50% depth of discharge (DoD):
Step 5: Choose Your Inverter
Size the inverter for peak simultaneous load plus 25% headroom:
Summary Formulas
| Component | Formula |
|---|---|
| Daily Load | Σ (Qty × W × Hours) |
| Solar Panels | Daily Load ÷ 0.8 ÷ Peak Sun Hours |
| Battery (Ah) | (Load × Days) ÷ (Volts × DoD) |
| Inverter (VA) | Peak Load × 1.25 |
Get a Professional Load Assessment
While this guide gives you a solid starting point, Bluedrop offers free professional load assessments where our engineers assess your actual consumption and design a system precisely for your needs.